Activated carbon for electric double layer capacitor electrode and method for producing the activated carbon

Abstract

The present invention provides a method for producing an activated carbon for an electric double layer capacitor, with which the wettability of a carbon material with an alkali activator is improved, thereby improving contact efficiency between the carbon material and the alkali activator and efficiently promoting reaction between the carbon material, which is a starting material and the activator. The method comprises adjusting a carbon material as it is or after having been calcined to produce a carbon powder having an average particle diameter of 0.5 to 15 μm, oxidizing the carbon powder to contain 3 percent by mass or more of oxygen, and activating the oxidized product with an alkali activator.

The invention claimed is: 
     
       1. A method for producing an activated carbon for an electric double layer capacitor electrode comprising:
 adjusting a green coke produced by delayed coking as it is or after having been calcined to produce a carbon powder having an average particle diameter of 0.5 to 15 μm; 
 oxidizing the carbon powder to contain 3 percent by mass or more and 15 percent by mass or less of oxygen; and 
 activating the oxidized product with an alkali activator. 
 
     
     
       2. The method for producing an activated carbon according to  claim 1  wherein the carbon material is graphitizable. 
     
     
       3. The method for producing an activated carbon according to  claim 1  wherein the calcination temperature is from 500 to 900° C. 
     
     
       4. The method for producing an activated carbon according to  claim 1  wherein the mix ratio of the oxidized product and the alkali activator is in the range of the oxidized product: the alkali activator=1:1 to 1:4 (mass ratio).